1. Field of the Invention
The present invention relates to a double window processing apparatus for a television system, and in particular to an improved double/multi window processing apparatus for a television system which is capable of matching the synchronousnesses of a main image and a sub-image.
2. Description of the Background Art
As shown in FIG. 1, the conventional double window processing apparatus for a television system includes a main screen tuner 101 and a sub-screen tuner 104 receiving a high frequency signal inputted through an antenna ANT and outputting intermediate frequency signals IF1 and IF2, a main screen intermediate frequency processor 105 and a sub-screen intermediate frequency processor 102 processing the output signals from the main screen tuner 101 and the sub-screen tuner 104 and outputting combined image signals CVBS1 and CVBS2, a digital comb filter 103 for receiving the output signal CVBS1 from the main screen intermediate frequency processor 102 and separating the thusly received signal into a luminance signal Ym and a chrominance signal Cm, a double window processor 106 receiving the output signal CVBS2 of the sub-screen intermediate frequency processor 105 and separating the thusly received signal into a luminance signal Yp and a chrominance signal Cp, a luminance/chrominance switching unit 107 switching the luminance signal Ym and the chrominance signal Cm of the digital comb filter 103 and the luminance signal Yp and the chrominance signal Cp of the double window processor 106 and outputting one luminance signal Y and one chrominance signal C, and an image processor 108 receiving an output signal Y/C of the luminance/chrominance switching unit 107 and outputting primary color signals R, G, B to a CPT.
The operation of the above-described conventional television system will be explained.
The tuner 101 receives a high frequency signal such as NTSC-M, PAL-M, PAL-N through the antenna ANT and inputs the intermediate frequency signal IF1 into the main screen intermediate frequency processor 102.
At this time, the main screen intermediate frequency processor 102 outputs a combined image signal CVBS1. Therefore, the digital comb filter 103 receiving the combined image signal CVBS1 separates the received signal into a luminance signal Ym and a chrominance signal Cm.
Therefore, the luminance/chrominance switching unit 107 switches the luminance signal Ym and the chrominance signal Cm separated by the digital comb filter 103 and outputs to the image processor 108, so that the primary color signals R, G, B are outputted to the CPT and are displayed on the screen.
In the case of the double windows, the tuner 104 receives the high frequency signal received from the antenna ANT and inputs the intermediate frequency signal IF2 into the sub-screen intermediate frequency processor 105.
At this time, the sub-screen intermediate frequency processor 105 inputs the combined image signal CVBS2 into the double window block 106.
The double window processor 106 receives the combined image signal CVBS2 of the sub-screen intermediate frequency processor 105 and separates the thusly received signal into the luminance signal Yp and the chrominance signal Cp and outputs to the luminance/chrominance switching unit 107.
The luminance/chrominance switching unit 107 receives the chrominance signal Ym and chrominance signal Cm of the digital comb filter 103 and the luminance signal Yp and the chrominance signal Cp of the double window processor 106 and switches each component of the same and outputs one luminance signal Y and one chrominance signal C to the image processor 108.
Therefore, the signals are combined into primary color signals R, G, B by the image processor 108, and are outputted to the CPT and displayed on the double window screen.
In the conventional art, when implementing a double window in the 3-system, the resolution of the images is decreased due to the mismatching of the main image and sub-image.
Accordingly, it is an object of the present invention to provide a double/multi window processing apparatus for a television system which overcomes the aforementioned problems encountered in the background art.
It is another object of the present invention to provide a double/multi window processing apparatus for a television system which is capable of preventing a synchronous distortion of a main screen image and a sub-screen image in the double/multi window mode by matching the synchronousness of the main screen image and sub-screen image and generating a signal for the double/multi-window image for thereby implementing a clearer image.
It is another object of the present invention to provide a double/multi window processing apparatus for a television system which is capable of judging a corresponding system, removing an interference bit, and stabilizing a synchronousness when there is not a signal when displaying an original screen of the 3-system NTSC-M, PAL-M, PAL-N based on the double/multi-window image.
To achieve the above objects, there is provided a double/multi window processing apparatus for a television system according to a first embodiment of the present invention which includes a first luminance/chrominance separator for separating a combined image signal of a main image outputted from an intermediate frequency processor into a luminance signal and a chrominance signal, a second luminance/chrominance separator for separating the combined image signals of the main image and subimage outputted from the intermediate frequency processor into a luminance signal and a chrominance signal, matching the synchronousnesses of the same, combining the synchronous matched luminance signal and chrominance signal and generating a double window luminance/chrominance signal, and a luminance/chrominance switching unit for switching the luminance and chrominance signals of the first and second luminance/chrominance separator in the double window mode and outputting one luminance and chrominance signal.
To achieve the above objects, there is provided a double/multi window processing apparatus for a television system according to a second embodiment of the present invention which includes a first luminance/chrominance separator for separating a combined image signal of a main image outputted from an intermediate frequency processor into a luminance signal and a chrominance signal, a second luminance/chrominance separator for separating a combined image signal of a main image outputted from the intermediate frequency processor into a luminance signal and a chrominance signal, matching the synchronousnesses of the same, combining the synchronous matched luminance and chrominance signals, and generating a double window luminance/chrominance signal and a multi window primary color signal, a luminance/chrominance switching unit for switching the luminance signal and chrominance signal of the first and second luminance/chrominance separator in the double window mode and outputting one luminance and chrominance signal, an image processor for processing a luminance signal and chrominance signal of the luminance/chrominance switching unit in the double window mode, processing a primary signal of the second luminance/chrominance separator in the multi window mode, and outputting the processed signal to a display unit, a synchronous stabilizer for grounding an external synchronous terminal of the image processor to a ground circuit for stabilizing the synchronousness of the non-signal screen in the double/multi window mode, and a controller for checking the second luminance/chrominance separator and image processor when selecting an auto program or a channel, judging a system information, storing the same, and controlling the operation of each element in accordance with the double/multi window setting.
Additional advantages, objects and features of the invention will become more apparent from the description which follows.